STAT 200 Fall 2012 OL4

STAT 200 Fall 2012 OL4 (due 11/11)

What is the level of measurement for each of the following:

Final grades in this class

Grade points Average (GPA)

Weights of newborn babies

Pounds

Seasons of the year

Ordinal measure (1-spring, 2-summer etc.)

Boiling temperatures of different liquids

Fahrenheit

Types of sampling used

I collect data from my class

Systematic Sampling

Data from every fourth patient in the hospital

Random Sampling

Data from 400 randomly … in criminal justice.

Stratified Random Sampling

Data from 4230 adults …were randomly generated

Random Sampling

The following data were collected on amounts of lawn debris after the major storm this past summer:

Pounds

Frequency

Class Boundaries

Mid-point

2-5

2

1.5-5.5

3.5

6-9

2

5.5-9.5

7.5

10-13

6

9.5-13.5

11.5

14-17

15

13.5-17.5

15.5

What is the class width?

The class Width is 3.

The weekly salaries for teachers of different grade levels at my school are as follows:

774 649 1210 546 431 612

Do the different grades have much variation in salary? Base your decision on the calculated standard which needs to be part of your solution.

Solution:

Yes, there exists significant variation in the salaries with respect to different grades of the teachers. This Can be clearly seen that the minimum salary is 431 and maximum salary is 1210 i.e. Range = Max - Min = 1210 - 431= 779, which certainly a huge difference. In fact this gap is above all the salaries at different grades.

5. I counted the number of words on each posting from my Class Announcements and found the following:

128130133137138142142144147149151151 151155156161163163166172

What is the 5-number summary?

Descriptive Statistics

 

 

Mean

148.95

Median

150

Mode

151

Standard Deviation

12.35643876

Range

44

Minimum

128

Maximum

172

A study compared cognitive behavioral therapy (CBT) and regular talk therapy for patients with anxiety. It was found that among 73 patients treated with CBT, there was a 92% success rate. Among 83 patients treated with regular talk therapy, there was a 72% success rate. Calculations using these results showed if there really is no different in success rates between CBT and regular talk therapy, then there is about a one chance in 1000 (1/1000) of getting success rates like these.

Should we conclude that CBT is better than regular talk therapy for anxiety?

Yes, with the above results and conditions we can conclude that CBT is better than regular talk therapy for anxiety.

Does the result have statistical significance? Why or why not?

No, the results have statistical significance because the chances of getting success rates like these are very low i.e. 0.001 which is a very low probability of accepting this success rate.

Does the result have practical significance? Why or why not?

It might have practical significance because of the reason that psychodynamic therapies are found to be significant in curing the patients from the mental diseases.

Should we recommend CBT for treatment of anxiety?

Statistically it should not be recommended but practically it can be recommended.

My cousin was 38 when she retired from the military. Most people who retire have a mean age of 43.8 years. The standard deviation is 8.9 years.

What is the difference between my cousin's age and the mean age?

Mean Age - Cousin's Age = 43.8 - 38 =5.8 Years

How many standard deviations is that (difference found in part a)?

The difference found in Part 'a' has almost 1 Standard ...